JP6194841B2 - Equalizing discharge device - Google Patents

Description

  The present invention relates to an equalizing discharge device that equalizes a remaining capacity of a secondary battery constituting an assembled battery.

  Hybrid vehicles and electric vehicles use assembled batteries in which a plurality of secondary batteries (battery cells) are connected in series to increase the output voltage. In such an assembled battery, when charge and discharge are repeated, the remaining capacity of each battery cell varies. When charging / discharging an assembled battery, in order to avoid overdischarge and overcharge of each battery cell, charge / discharge of the assembled battery is performed according to the minimum or maximum remaining capacity of each of the plurality of battery cells. Must stop. When the variation in the remaining capacity of each battery cell is large, the usable battery capacity is lowered, so that it is necessary to equalize the remaining capacity of each battery cell.

  As a method of equalizing the remaining capacity of each battery cell, the remaining capacity of each battery cell is calculated from the no-load voltage (open end voltage) of each battery cell, and the discharge amount of each battery cell is calculated from the remaining capacity. And the technique which discharges with respect to the discharge circuit from each battery cell for the discharge time set based on the discharge amount is known (for example, patent document 1).

JP 2007-244142 A

  In the technique described in the above-mentioned patent document, the discharge time flowing from the battery cell to the discharge circuit is regarded as constant, and the discharge time is calculated by dividing the discharge amount by the discharge current. Here, the discharge current changes depending on the state of the secondary battery used as the battery cell and the state of the discharge circuit. That is, in the above-described technique in which the discharge time flowing from the battery cell to the discharge circuit is regarded as constant and the discharge time is calculated, and the discharge from the battery cell to the discharge circuit is performed for the discharge time, the battery cell is actually discharged. The amount of discharge cannot be made a desired amount.

  The present invention has been made to solve the above-described problems, and aims to accurately equalize the remaining capacity of each secondary battery when equalizing the remaining capacity of the secondary battery constituting the assembled battery. To do.

  In the assembled battery (10) configured by connecting a plurality of secondary batteries (C1 to Cn) in series, the present invention provides the plurality of secondary batteries in order to equalize the remaining capacity of the plurality of secondary batteries. An equalizing discharge device (20) for discharging from a battery to a discharge circuit (21), respectively, a voltage detection means (22) for detecting a voltage between terminals of the secondary battery, and starting the discharge And a required discharge amount calculating means (31) for calculating a required discharge amount required for equalizing the remaining capacity in the secondary battery based on the detected value of the voltage between the terminals, and for each predetermined cycle, An actual discharge amount calculating means (32, 34) for calculating an actual discharge amount of the secondary battery in the discharge circuit based on a detected value of a voltage between terminals of the secondary battery, and an integrated value of the actual discharge amount is the From the secondary battery until the required discharge amount is reached And discharge means for executing the discharge to the discharge circuit (37), characterized in that it comprises a.

  According to the equalizing discharge apparatus of the present invention, at the start of the equalizing discharge, a necessary discharge amount that is a discharge amount necessary for equalization is calculated for each secondary battery. During the equalization discharge, the actual discharge amount in the discharge circuit is calculated based on the detected value of the inter-terminal voltage of the secondary battery for each predetermined period. The equalized discharge is continued until the integrated value of the actual discharge amount reaches the required discharge amount.

  By performing such control, even when the voltage between the terminals of the secondary battery fluctuates due to the equalizing discharge during the equalizing discharge, the actual discharge amount can be reduced in consideration of the fluctuation. Calculated. This makes it possible to bring the amount of discharge required for equalization (target value) close to the amount of discharge actually discharged from the secondary battery (actual value), and accurately determine the remaining capacity of each secondary battery. It becomes possible to equalize.

The electrical block diagram of this embodiment. The figure which shows the SOC-OCV characteristic of an olivine type lithium ion secondary battery. The functional block diagram showing the function of a control part. The flowchart showing a required discharge amount calculation process. The flowchart showing a discharge current calculation process. The flowchart showing an update period setting process. The flowchart showing the remaining discharge amount update process.

  FIG. 1 shows an electrical configuration diagram of the assembled battery 10 and the equalizing discharge device 20 in the present embodiment.

  The assembled battery 10 is configured as a series connection body of n battery cells C1 to Cn (n is an integer of 2 or more). Each battery cell C1-Cn is a lithium ion secondary battery. Furthermore, each battery cell C1-Cn is an olivine type lithium ion secondary battery in which lithium iron phosphate (LiFePO4) having an olivine structure is included as a positive electrode material. In addition, as the positive electrode material of each battery cell C1 to Cn, lithium metal phosphate having another olivine structure such as lithium manganese phosphate (LiMnPO4), lithium cobalt phosphate (LiCoPO4), lithium nickel phosphate (LiNiPO4), etc. Acid salts may be used.

  The remaining capacity-open circuit voltage (OCV) characteristics of the olivine-based lithium ion secondary battery are shown in FIG. Note that a state of charge (SOC) representing a ratio of the remaining capacity to the full charge capacity is used as an index representing the remaining capacity.

  In the region where the SOC is A1 to A2 (for example, A1 = 20%, A2 = 80%), the OCV hardly changes even if the SOC changes. A region where the SOC is A1 to A2 is referred to as a plateau region. In the region where the SOC is less than A1 and the region where the SOC is greater than A2, the OCV increases remarkably as the SOC increases compared to the plateau region. The region where the SOC is less than A1 and the region where the SOC is greater than A2 are called non-plateau regions. In the olivine-based lithium ion secondary battery, the plateau region is wider and the change in the OCV in the plateau region is smaller than in lithium ion secondary batteries other than the olivine-based battery.

  Returning to the description of FIG. 1, the assembled battery 10 is connected to the equalizing discharge device 20. The discharge circuit 21 of the equalizing discharge device 20 includes resistors R1 to Rn and semiconductor switches SW1 to SWn. The battery cell Ci is connected in parallel with a series connection body of the resistor Ri and the semiconductor switch SWi, and the battery cell Ci, the resistor Ri, and the semiconductor switch SWi form a closed circuit (i = 1 to n). When the semiconductor switch SWi is turned on, the battery cell Ci discharges the resistor Ri.

  Further, both terminals of the battery cells C1 to Cn are respectively connected to a cell voltage detection circuit 22 as voltage detection means. The cell voltage detection circuit 22 detects the voltage between the terminals of the battery cells C1 to Cn. Further, the circuit board on which the discharge circuit 21 is provided is provided with a temperature sensor 23 as temperature detecting means, and detects the substrate temperature of the discharge circuit 21.

  The control unit 30 acquires the detection values V1 to Vn of the inter-terminal voltages of the battery cells C1 to Cn from the cell voltage detection circuit 22, and acquires the detection value T of the substrate temperature of the discharge circuit 21 from the temperature sensor 23. The controller 30 equalizes the SOCs of the battery cells C1 to Cn by performing on / off control of the semiconductor switches SW1 to SWn of the discharge circuit 21 based on the detection values V1 to Vn, T. The control unit 30 in the present embodiment calculates a target SOC based on the SOC1 to SOCn of each battery cell C1 to Cn, and each battery cell C1 to Cn so that the SOC of each battery cell C1 to Cn becomes the target SOC. To the resistors R1 to Rn.

  A functional block diagram of the control unit 30 is shown in FIG. The control unit 30 includes a necessary discharge amount calculation unit 31, a discharge current calculation unit 32, an update cycle setting unit 33, a switch control unit 37, and a remaining discharge amount update unit 38. The control unit 30 controls the switch SWi to discharge the battery cell Ci so as to reduce the SOCi of the battery cell Ci to the target SOC determined from the SOC1 to SOCn of the battery cells C1 to Cn (i = 1). ~ N).

  The required discharge amount calculation means 31 calculates a required discharge amount DCi that is a discharge amount necessary for the battery cells Ci in order to equalize the SOC1 to SOCn of the battery cells C1 to Cn. The required discharge amount calculation means 31 acquires the detected values V1 to Vn of the inter-terminal voltages of the battery cells C1 to Cn under a situation where the discharge is not performed in the battery cells C1 to Cn. In this case, the detected values V1 to Vn of the inter-terminal voltage acquired by the required discharge amount calculating means 31 are equal to the OCV of each of the battery cells C1 to Cn.

  The required discharge amount calculating means 31 uses the SOC-OCV map shown in FIG. 2 based on the acquired detected values V1 to Vn of the inter-terminal voltages of the respective battery cells C1 to Cn, and the SOC1 to SOC1 of each battery cell C1 to Cn. Calculate SOCn. Then, the target SOC of each battery cell C1 to Cn is calculated based on the SOC1 to SOCn of each battery cell C1 to Cn. Then, in order to equalize the SOCs of the battery cells C1 to Cn by reducing the SOCi of the battery cell Ci to the target SOC, the necessary discharge amount DCi necessary for the battery cell Ci is calculated.

  The remaining discharge amount storage means 36 stores the required discharge amount DCi calculated by the required discharge amount calculation means 31. When the discharge from the battery cell Ci is carried out, the subtracting means 35 requires the required discharge as the remaining discharge amount stored in the remaining discharge amount storage means 36 based on the actual discharge amount actually discharged from the battery cell Ci. Update the quantity DCi. The switch control means 37 (discharge execution means) turns on the switch SWi until the required discharge amount DCi reaches 0 Ah, and controls the switch SWi to the off state when the required discharge amount DCi reaches 0 Ah. That is, the switch control unit 37 performs the discharge from the battery cell Ci to the discharge circuit 21 until the integrated value of the actual discharge amount reaches the necessary discharge amount DCi calculated by the necessary discharge amount calculating unit 31.

  The discharge current calculation means 32 acquires the detection values Vi and T. The discharge current calculation unit 32 calculates the on-resistance value Ron of the switch SWi based on the detected value T of the substrate temperature of the discharge circuit 21. Then, by dividing the detected value Vi of the voltage across the terminals of the battery cell Ci by the sum of the on-resistance value Ron of the switch SWi and the resistance value R of the resistor Ri, the discharge current Iout flowing from the battery cell Ci to the discharge circuit 21 is obtained. Calculate (Iout = Vi / (Ron + R)).

  The multiplication unit 34 calculates a product Iout · λ of the discharge current Iout and the update period λ of the required discharge amount DCi. The subtracting means 35 subtracts the multiplication value Iout · λ as the actual discharge amount actually discharged from the battery cell Ci from the required discharge amount DCi stored in the remaining discharge amount storage means 36, thereby obtaining the remaining discharge amount. The required discharge amount DCi stored in the storage means 36 is updated. That is, the discharge current calculation unit 32 and the multiplication unit 34 constitute an actual discharge amount calculation unit. The subtracting means 35 and the remaining discharge amount storage means 36 constitute a remaining discharge amount updating means 38 for sequentially updating the required discharge amount DCi as the remaining discharge amount.

  The update cycle setting means 33 calculates the update cycle λ of the required discharge amount DCi based on the current SOC of the battery cell Ci. Specifically, when the current SOCi of the battery cell Ci belongs to the plateau region A1 to A2, the update cycle λ is set to λ1, and the current SOC of the battery cell Ci is 0 in the non-plateau region. When it belongs to% to A1 or A2 to 100%, the update period λ is set to λ2.

  Here, λ1 is set to a value larger than λ2. That is, when the SOCi of the battery cell Ci belongs to the non-plateau region, the update period of the required discharge amount is set shorter than when the SOCi of the battery cell Ci belongs to the plateau region. By performing such setting, it is possible to increase the frequency of updating the required discharge amount when the SOCi of the battery cell Ci belongs to the non-plateau region, and improve the calculation accuracy of the required discharge amount.

  FIG. 4 is a flowchart showing the required discharge amount calculation process. This process is performed by the required discharge amount calculation means 31 at the start of the equalization discharge of the battery cell Ci.

  In step S11, detection values V1 to Vn of the inter-terminal voltages of the battery cells C1 to Cn are acquired. Here, since no current flows in each of the battery cells C1 to Cn, the detected values V1 to Vn of the inter-terminal voltage are equal to the OCV of each of the battery cells C1 to Cn. In step S12, SOC1 to SOCn, which are the SOCs of the battery cells C1 to Cn, are calculated based on the detection values V1 to Vn as the OCV of the battery cells C1 to Cn.

  In step S13, the required discharge amount DCi in the battery cell Ci is calculated based on the SOC1 to SOCn, and the process ends. In the calculation of the required discharge amount DCi, the minimum one of SOC1 to SOCn is set as the target SOC, the deviation between the target SOC and SOCi is calculated, and the required discharge amount is calculated as the product of the deviation and the full charge capacity of the battery cell Ci. DCi is calculated. An average value of SOC1 to SOCn may be set as the target SOC.

  FIG. 5 is a flowchart showing the discharge current calculation process. This process is performed by the discharge current calculation means 32 at a predetermined cycle during the equalization discharge.

  In step S21, the detected value Vi of the voltage between the terminals of the battery cell Ci and the detected value T of the substrate temperature of the discharge circuit 21 are acquired. In step S22, the on-resistance value Ron of the switch SWi of the discharge circuit 21 is calculated based on the detected value T of the substrate temperature of the discharge circuit 21. Specifically, the detected value T of the substrate temperature of the discharge circuit 21 is regarded as the temperature of the switch SWi, and the on-resistance value Ron is calculated using a map showing the correspondence between the temperature of the switch SWi and the on-resistance value Ron. In step S23, the discharge current Iout flowing from the battery cell Ci to the resistor Ri and the switch SWi of the discharge circuit 21 is calculated, and the process ends. Specifically, the discharge current Iout is calculated as a value obtained by dividing the detected value Vi of the inter-terminal voltage of the battery cell Ci by the sum of the resistance value R of the resistor Ri and the on-resistance value Ron of the switch SWi (Iout = Vi / (R + Ron)).

  FIG. 6 is a flowchart showing the update cycle setting process. This process is performed at predetermined intervals by the update cycle setting means 33.

  In step S31, SOCi that is the SOC of the battery cell Ci to be discharged is acquired. The SOCi can be calculated based on the detected value Vi of the inter-terminal voltage of the battery cell Ci and the discharge current Iout discharged from the battery cell Ci. In step S32, it is determined whether or not the SOCi of the battery cell Ci belongs to A1 to A2 that are plateau regions. When the SOCi of the battery cell Ci belongs to the plateau region (S32: YES), in step S33, the update period λ of the required discharge amount DCi is set to λ1, and the process is terminated. If the SOC of the battery cell Ci does not belong to the plateau region, that is, belongs to the non-plateau region (S32: NO), the update period λ of the required discharge amount DCi is set to λ2 (λ1> λ2) in step S34. The process is terminated.

  FIG. 7 is a flowchart showing the remaining discharge amount update process. This process is performed by the remaining discharge amount update unit 38 for each update cycle λ.

  In step S41, the required discharge amount DCi is acquired. Regarding the acquisition of the required discharge amount DCi, the first time is acquired from the required discharge amount calculation means 31 and then from the remaining discharge amount storage means 36. In step S 42, the amount of discharge Iout · λ generated by the discharge current Iout flowing from the battery cell Ci to the discharge circuit 21 during the previous update cycle is acquired from the multiplying unit 34. In step S43, the required discharge amount DCi is updated. Specifically, a value obtained by subtracting the discharge amount Iout · λ from the required discharge amount DCi is stored in the remaining discharge amount storage means 36 as a new required discharge amount DCi.

  In step S44, the updated required discharge amount DCi is compared with 0 Ah. If the updated necessary discharge amount DCi is greater than 0 Ah (S44: YES), the process waits until the update period λ elapses (S45: NO) in step S45, and when the update period λ elapses (S45: YES), again. The process after step S41 is performed. When the updated required discharge amount DCi has reached 0 Ah (S44: NO), in step S46, the switch SWi is turned off to end the discharge, and the process is ended.

  Hereinafter, the effect which this embodiment show | plays is described.

  Even when the detected value Vi of the inter-terminal voltage of the battery cell Ci varies with the equalizing discharge during the equalizing discharge, the discharge current Iout is calculated in consideration of the variation. It becomes possible to make the discharge amount (target value) necessary for equalization close to the discharge amount (actual value) actually discharged from the battery cells Ci. By performing such control, it becomes possible to equalize the remaining capacities of the battery cells C1 to Cn accurately.

  Specifically, the necessary amount of remaining discharge is obtained by subtracting the multiplication value of the current discharge current Iout and the update cycle λ corresponding to the discharge amount discharged during the previous update cycle from the required discharge amount DCi. The discharge amount DCi is updated. Then, the discharge circuit 21 is discharged until the required discharge amount DCi as the remaining discharge amount becomes 0 Ah.

  In the plateau region, the change in OCV accompanying the discharge is slight, so that the change in the detected value Vi of the voltage between the terminals of the battery cell Ci caused by the discharge hardly occurs, and the change in the discharge current Iout over time is considered to be small. On the other hand, in the non-plateau region, the OCV change due to the discharge is large, the change in the detected value Vi of the inter-terminal voltage of the battery cell Ci due to the discharge is large, and the time change of the discharge current Iout is also large.

  Therefore, the update cycle λ2 of the required discharge amount DCi in the non-plateau region is set shorter than the update cycle λ1 of the required discharge amount DCi in the plateau region, and a large number of update opportunities of the required discharge amount DCi in the non-plateau region is set. It was. By adopting such a configuration, it is possible to improve the accuracy of the equalizing discharge when the SOC belongs to the non-plateau region and to simplify the process when the SOC belongs to the plateau region.

  In the present embodiment, olivine-based lithium ion secondary batteries are used as the battery cells C1 to Cn. In the olivine-based lithium ion secondary battery, the change in OCV in the plateau region is extremely small compared to the change in OCV in the non-plateau region, and the plateau region is wide. For this reason, the effect by changing update period (lambda) by said plateau area | region and non-plateau area | region becomes remarkable.

  The discharge circuit 21 includes resistors R1 to Rn and semiconductor switches SW1 to SWn. Since the on-resistance value Ron of the semiconductor switches SW1 to SWn increases as the temperature rises due to heat generation of the semiconductor switches SW1 to SWn due to the equalizing discharge, the influence on the equalizing discharge is increased. Therefore, in the present embodiment, as the resistance value of the discharge circuit 21, a value obtained by adding the resistance value R of the resistors R1 to Rn and the on-resistance value Ron of the semiconductor switches SW1 to SWn is used. This makes it possible to calculate the value of the discharge current Iout more accurately than in a configuration in which only the resistance value R of the resistors R1 to Rn is regarded as the resistance value of the discharge circuit 21.

  When discharging is performed, a current flows through the semiconductor switches SW1 to SWn of the discharge circuit 21, and the semiconductor switches SW1 to SWn generate heat due to the current. When the temperature of the semiconductor switches SW1 to SWn increases due to heat generation, the on-resistance value Ron of the semiconductor switches SW1 to SWn increases. Therefore, the substrate temperature of the discharge circuit 21 is detected by the temperature sensor 23, the detected value T of the substrate temperature is regarded as the temperature of the semiconductor switches SW1 to SWn, and the on-resistance value Ron of the semiconductor switches SW1 to SWn is based on the temperature. It was set as the structure which calculates. With such a configuration, the value of the discharge current Iout can be calculated more accurately.

(Other embodiments)
In the above configuration, the required discharge amount DCi is updated based on the calculated value of the discharge current Iout regardless of the SOC. When this is changed, and at least one of the SOC before the equalization discharge and the target SOC corresponding to the value obtained by subtracting the required discharge amount from the remaining capacity before the discharge belongs to the non-plateau region, the voltage between the terminals of the battery cell Ci The discharge current Iout is calculated based on the detected value Vi. And it is set as the structure which updates the present required discharge amount DCi based on the discharge current Iout. With this configuration, it is possible to simplify the processing while suitably equalizing the remaining capacities of the battery cells C1 to Cn.

  The required discharge amount may be set as the total discharge time, and the subtraction time corresponding to the actual discharge amount may be calculated every time the update period λ elapses. Specifically, when the discharge current Iout increases, the subtraction time is calculated to be longer, and when the discharge current Iout decreases, the subtraction time is calculated to be shorter. The semiconductor switches SW1 to SWn are turned on until the total discharge time becomes 0 sec.

  -Although the olivine type lithium ion secondary battery was used as battery cell C1-Cn, this may be changed and lithium ion secondary batteries other than an olivine type may be used. Even in a lithium ion secondary battery other than the olivine system, there are a plateau region and a non-plateau region. Therefore, if the update period λ of the required discharge amount DCi is changed in the plateau region and the non-plateau region, the olivine-based lithium ion secondary battery Similar effects can be obtained. Moreover, it is good also as a structure which uses a nickel-hydrogen secondary battery, a lead secondary battery, etc. as battery cell C1-Cn.

  The on-resistance value Ron of the semiconductor switches SW1 to SWn is calculated based on the detected value T of the substrate temperature, but this may be changed and a fixed value may be used as the on-resistance value Ron. Further, instead of the detected value T of the substrate temperature, the temperature of the semiconductor switches SW1 to SWn may be directly detected and the detected value may be used. Further, as the resistance value of the discharge circuit 21, the on-resistance value Ron of the semiconductor switches SW1 to SWn may be ignored, and the discharge current Iout may be calculated using the resistance value R of the resistors R1 to Rn.

  The update cycle setting means determines the SOC of the battery cell at the start of discharge when one of the SOC of the battery cell at the start of the equalization discharge and the target SOC that is the target value of the equalization discharge belongs to the non-plateau region. In addition, the update cycle may be set shorter than when both the target SOCs belong to the plateau region.

  Although the update cycle λ is changed between the non-plateau region and the plateau region, this may be changed and the required discharge amount DCi may be updated at the same update cycle λ.

  DESCRIPTION OF SYMBOLS 10 ... Assembly battery, 20 ... Equalization discharge apparatus, 21 ... Discharge circuit, 22 ... Cell voltage detection circuit, 31 ... Necessary discharge amount calculation means, 32 ... Discharge current calculation means, 34 ... Multiplication means, 37 ... Switch control means, 38: Remaining discharge amount update means, C1-Cn: Battery cells.

Claims (6)

In the assembled battery (10) configured by connecting a plurality of secondary batteries (C1 to Cn) in series, in order to equalize the remaining capacity of the plurality of secondary batteries, a discharge circuit is formed from the plurality of secondary batteries. (21) An equalizing discharge device (20) for performing discharge with respect to each,
The secondary battery has, as remaining capacity-open voltage characteristics, a plateau region in which a change in open voltage due to a change in remaining capacity is small, and a non-plateau region in which a change in open voltage due to a change in remaining capacity is large. ,
Voltage detection means (22) for detecting a voltage between terminals of the secondary battery;
Required discharge amount calculating means (31) for calculating a necessary discharge amount for equalizing the remaining capacity in the secondary battery based on the detected value of the voltage between the terminals when starting the discharge; ,
During the implementation of the discharge, to obtain the detected value of the inter-terminal voltage before Symbol secondary battery for each predetermined period, it said in the discharge circuit based on the detected value of the terminal voltage of the acquired battery two Actual discharge amount calculating means (32, 34) for calculating the actual discharge amount of the secondary battery;
Discharge execution means (37) for performing discharge from the secondary battery to the discharge circuit until the integrated value of the actual discharge amount reaches the required discharge amount;
Period setting means (33) for setting the predetermined period to be shorter when the remaining capacity of the secondary battery belongs to the non-plateau region than when the remaining capacity of the secondary battery belongs to the plateau region;
An equalizing discharge device comprising: There is provided a remaining discharge amount update means (38) for updating a remaining discharge amount which is a remaining discharge amount necessary for equalization by subtracting the actual discharge amount from the required discharge amount at each predetermined period. ,
2. The equalizing discharge apparatus according to claim 1, wherein the discharge execution unit performs discharge from the secondary battery to the discharge circuit until the remaining discharge amount becomes zero. The discharge executing means is configured to provide the actual discharge when at least one of a remaining capacity of the secondary battery at the start of the equalizing discharge and a value obtained by subtracting the required discharge amount from the remaining capacity belongs to the non-plateau region. equalization discharge device according to claim 1 or 2 which comprises carrying out the discharging of the discharge circuit based on the actual discharge amount calculated by the amount-calculating means. The said secondary battery is an olivine type | system | group lithium ion secondary battery in which the lithium metal phosphate of the olivine structure is used as the positive electrode material , The any one of Claim 1 thru | or 3 characterized by the above-mentioned. Equalizing discharge device. The discharge circuit includes resistors (R1 to Rn) and open / close means (SW1 to SWn), and discharges the resistor from the secondary battery when the open / close means is turned on. Because
The actual discharge amount calculating means calculates a discharge current by dividing the detected value of the voltage between the terminals by a combined value of the resistance value of the resistor and the on-resistance value of the switching means, and based on the discharge current equalization discharge device according to any one of claims 1 to 4, characterized in that to calculate the actual discharge amount. Temperature detection means (23) for detecting the substrate temperature of the discharge circuit;
A resistance value calculating means (32) for calculating an on-resistance value of the opening / closing means based on a detected value of a substrate temperature of the discharge circuit;
The equalizing discharge apparatus according to claim 5 , comprising:

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